1. Field of the Invention
This invention relates to a semiconductor integrated circuit having a reconfigurable circuit wherein a circuit structure thereof can be changed according to an external signal input to a configuration memory or the like, and a test method therefor.
2. Related Art
In recent years, a reconfigurable circuit wherein a circuit structure thereof can be changed according to an external signal or the like has been further demanded due to its flexibility of use.
However, it has been pointed out that because in such a reconfigurable circuit, (1) its structure is variable and (2) chip cost increases if a probe pad is disposed therein, this circuit is difficult to test.
FIG. 1 shows a test method for a conventional reconfigurable circuit.
Upon testing, first, the reconfigurable circuit 110 is constructed with reconfigurable function units (RFU) 111 such as parallel multiplier or the like, according to an external data SO. Then, for example, multiplication data X, Y are inputted to the input side of this RFU 111 and output Z is obtained so as to verify whether or not an error occurs.
However, according to the aforementioned conventional test method, the combination of the input vectors X, Y increases tremendously and the number of output pins for verifying the output Z also increases. Further, to verify output data, a high speed tester corresponding to internal operation frequency is needed, so that the circuit test becomes complicated.